1. Field of the Invention
This invention relates generally to automated labeling equipment for labeling articles, and more particularly to a label placement machine that includes a label shuttle and clamp bar assembly, and most particularly to a label placement machine in which the label shuttle transports the printed label from a label supply area to a label applicator head retrieval area.
2. Discussion of the Related Art
The application of labels to articles and products has been and continues to be an important step in providing pertinent information about the article or product. Manufacturers of various products are continually seeking a more efficient manner in which to apply labels to articles or items, such as printed circuit boards, cartons, containers or any other packages or products having a surface capable of securely receiving an adhesive label.
Various methods have been employed in the past to mark articles, most traditionally by manual application of stickers or labels. The introduction of adhesive backed pressure sensitive labels and hand-held, manually operated applicators has greatly facilitated the marking of articles by providing a simple means for applying an adhesive-backed label to an article. Such manual application of labels is well known and used extensively. Their use, however, in manufacturing, assembling and distributing applications is limited because of the necessity for marking articles at high speed. In these applications, the articles to be labeled are transported along a conveyor belt past a numbers of stations, one of which often entails the application of a label to each article as it passes by or while the conveyor belt is stopped. Manual application of labels in this high-speed operation is unacceptably slow, inefficient, labor intensive and therefore, impractical due to the time constraints associated with high volume production.
As a result, automated labeling machines have been developed to apply labels to articles advancing by a labeling station on, for example, a conveyor belt. The pressure-sensitive labels are commonly precut and carded on a continuous web of material, often called a backing material, which is rolled into a roll for mounting on the labeling machine. The backing material is somewhat more flexible than the label itself. This allows the label to be separated from the backing material simply be bending the backing material sharply away from the label, which is usually done by drawing the backing over a fairly sharp stripping or peeling edge of a peel blade or plate. The less flexible label then separates from the backing material.
One type of labeling machine includes the use of a movable label applicator assembly for acquiring the label from the peel blade, moving transversely across the conveyor away from the peel blade and applying the label to the article. One of the problems that have been encountered is the accuracy of the label placement on the article. The placement of the label on the label applicator assembly usually varies each time the applicator assembly acquires the label in the dispensing position. Each label that goes over the peel blade may release slightly differently from the backing material. This may skew the label when it is dispensed onto the receiving surface of the label applicator assembly. It has also been found that during movement of the label applicator assembly from the dispensing position to the article, the label often inadvertently moves relative to the receiving surface due machine vibration, abrupt movements and inertial and wind forces on the label. This inadvertent movement of the label during retrieval and movement of the label applicator assembly is even more a problem in high speed operations and results in unpredictable label positioning and label orientation on the article. Consequently, the location and orientation of the label on the article may be undesirable and unacceptable. Moreover, these types of machines often require the label applicator assembly to move through a delivery stroke from the peel blade and a return stroke back to the peel blade for each dispensed label, thereby expending a significant amount of operating time for each label. This unnecessarily large amount of operating time per label makes it more difficult to obtain the high speed labeling desired in present applications.
Nevertheless, industry demand for increased productivity continues to generate a need for higher speeds of operation. In most modem automated facilities, the placement of labels is the most time consuming. Instead of making label placement movements singly, in successive steps, it would be convenient, and faster, to make two or more movements simultaneously, to save valuable time. Furthermore, there is a need for accurate placement of labels on articles. In such cases, the label placement machine must be able to accommodate rapid changes not only label placement, but label types and sizes. It should therefore be clear that an accurate and reliable label placement machine that places labels quickly and accurately on an article would constitute a significant advance in the art.